Ben's Electric Bike.
 

Well Here it is, starting the project off with a 20in Redline Bmx Bike.. All steel frame etc. Its a nice bike to begin with, steel frame and some decent wheels.


To power it I have one of these big ass brushed electric motors that i have laying around- and a 16:1 gear reduction box. Also picked up some 35 chain and sprokets for drive... BrianG- your gearing calculator is a life saver.. have it spec'd out at 22mph on 6s lipo. with low gearing and lots of reduction it should keep amp draw relatively low.

Just a project to get me from point A to point B being as lazy as possible.

Planning on making a steel subframe/ motor mount and weld it to the existing frame.


Pictures will be up later today.

Here is the bike..


Is there any way to directly control a speed controller with something like a potentiometer?

I can get a twist grip for an electric scooter if there is any way make it work.

if not, does anyone have or know how to make a cheap servo tester?

"Bad lutach first"

You know what's coming for you Ben :rofl:.

No Ben, don't do it. Steel is much harder then aluminum and if it bends, it'll be much harder to bend it back to it's original place :lol:. So have you fixed you mount yet :oops:.

"Good lutach second"

There are some very intelligent guys in the forum who has vast experience with such a project. I'm sure they'll be here guiding you.

You can use a servo tester for controlling the speed controller if you have an rc type controller.

Metalman had a link to a twist grip control that would run a rc type esc. Can't remember where he had it though.

I was in Academy Sports this past Saturday and stumbled upon the battery powered bicycles for him and her. They use a brushed motor like the electrics scooters do. They just basically adapted the scooter setup onto a bicycle.

Thanks luciano, but i have no problems with steel, it will be built with braces etc to stop from bending..

I know I can, but twist grip would be pretty neat


Yea, but the speed controllers they use are not as efficient or powerful as any Rc controllers. Im probably gonna use my MMM for the moment in this one.

A searchin' I will go.

THanks for the info guys.






Now, since i want to retain the stock pedal system- would i be able to set a slight drag brake on the MMM and use the regenerative abilities of the speed control to recharge the batteries? I dont know how much power the regen braking actually saves..

I can't wait to read the plea to castle to replace your MMM when you fry it - lol

"my e-bike shouldn't void the warranty, I only ran it on 6s....":lol:

i cant wait to see this!

velosolex
 

hey,

look at this:
http://motorbike-search-engine.co.uk...solex_5000.jpg

put the motor and the electronics to the front; batteries into the center of the frame. you will need a big outrunner, at hobbyking they have som 8cm monsters with about 250 r/min.

you could design a mount, where the motor gets - by pulling a lever - contact to the tire. so when you don't want to use the motor, no problem when going downhill very fast.

they have now designed a e-velosolex:
http://s3b.directupload.net/images/0...p/kyrfh4qp.jpg

anyways, cool idea, btw!!!!

just recently I saw a high-end e-bike on tv, fast like a motorbike.

brushless rulez :lol:

I'm not sure if they have this, but it would be neat to have a motor setup so that the more force you put on the pedals, the more motor assist there is. And you could set the relative assist amount. Wouldn't need a manual throttle this way.

hmm if you were to have a pressure sensitive potentiometer, on the pedal and have a proportional value applied to the speed controller.

Does anyone know if I can run two seperate speed control in series to a motor- like 4s on each for 8s to the motor... its brushed.

I'd say no as the FETS would be out of phase between the ESC's.

in a brushed motor?

I know for a fact you can't. I tried on my Brushed rs4, both esc's burned up instantly when applied throttle. Nice project ben, I put a weed eater motor on a chopper. Been crusin around on that. :intello:

I bet that sounds strange.

I remember seeing an electric bike on TV like 2 years ago or so, that would assist the rider depending on the load. Have no idea how it works, or who makes it (if it even went into production), but the idea does exist.

Fets still switch current in brushed mode

Couldn't find the bike with automatic assist, but I found a kit that was on the New Inventors show here a while ago.
http://www.abc.net.au/tv/newinventors/txt/s1781722.htm
And the company website http://www.elationebikes.com.au/ It could have some ideas worth using.